package com.geek.gkpush.util.collection;

import java.util.ArrayList;
import java.util.List;

/**
 * <h1>集合工具类。</h1><br/>
 *
 * <h1><br/><a href="https://u.geekbang.org/subject/arch3/100614201">Java 业务架构实战营：https://u.geekbang.org/subject/arch3/100614201</a></h1><br/><h1><a href="https://gitee.com/ylimhhmily/BizArchPracticeCamp">Java 业务架构实战营代码地址：https://gitee.com/ylimhhmily/BizArchPracticeCamp</a></h1><br/><h1><a href="https://u.geekbang.org/subject/java4th/1001148?source=app_share">高级 Java 工程体系课 2023 版：https://u.geekbang.org/subject/java4th/1001148?source=app_share</a></h1><br/><h1><a href="https://time.geekbang.org/column/intro/100312101?tab=catalog">Dubbo 源码剖析与实战：https://time.geekbang.org/column/intro/100312101?tab=catalog</a></h1>
 *
 * @author hmilyylimh
 * ^_^
 * @version 0.0.1
 * ^_^
 * @date 2023/9/29 08:51
 */
public class CollectionUtils {

    /**
     * <h2>合并多个集合。</h2>
     *
     * @param arr
     * @param <E>
     * @return
     */
    public static <E> List<E> mergeList(List<E>... arr) {
        if (arr == null || arr.length == 0) {
            return new ArrayList<>();
        }
        List<E> resultList = new ArrayList<>();
        for (List<E> itemArr : arr) {
            if (itemArr == null || itemArr.size() == 0) {
                continue;
            }
            resultList.addAll(itemArr);
        }
        return resultList;
    }
}